Trocar systems have been developed over the years for various endoscopic applications in the field of medicine. These trocar systems conventionally include a cannula through which a trocar or obturator or other endoscopic related tool extends. It is known to use one or more valves positioned within or connected to a proximal end of the cannula of a trocar system. Examples of such trocar systems having one or more valves in the cannula thereof are known. These devices, however, can be bulky and awkward to use, have complex multi-component mechanical valves which can be difficult and expensive to manufacture, and can have an increased risk of mechanical failure. The mechanical valves also have little or no flexibility.
Other trocar systems have been developed which are easier to use and have less complex mechanical valves. One example of such trocar system can be seen in U.S. Pat. No. 6,569,119 by Haberland et al., entitled “Trocar System Having Cannula with Finger Grips,” and other improvements can be seen in U.S. Patent Application publication no. 2006027675, entitled “Trocar and cannula assembly having conical valve and related methods,” and publications nos. 20060047293 and 20050165433, both entitled “Trocar having planar fixed septum seal and related methods,” and all by Haberland et al. These devices provide enhanced gripping and easier handling of the systems. Nevertheless, there is also still a need for alternative cannula and valve configurations for trocar systems, a need for relatively less expensive trocar systems, a need for trocar systems with better performance, and a need for more flexible trocar systems and valves which enhance handling thereof by medical personnel users, i.e., physicians, and yet are still effective for various endoscopic surgical procedures.